Accessing Near-Infrared-Absorbing BF2-Azadipyrromethenes via a Push–Pull Effect
摘要:
Novel aza-BODIPYs with significant bathochromic shifts were designed and synthesized by installation of strong electron-withdrawing groups on the para-positions of 1,7-phenyls and electron-donating groups on the para-positions of 3,4-phenyls. These dyes show strong NIR fluorescence emissions up to 756 nm, and absorptions up to 720 nm.
Diastereo- and Enantioselective Organocatalytic Direct Conjugate Addition of γ-Butenolide to Chalcones
作者:Yinan Zhang、Chenguang Yu、Yafei Ji、Wei Wang
DOI:10.1002/asia.201000014
日期:——
A diastereo‐ and enantioselectiveconjugateaddition reaction of γ‐butenolide with chalcones has been developed. Notably, unmodified γ‐butenolide was directly employed as a nucleophile in the Michael addition reactions. This process was catalyzed by a previously reported cyclohexane diamine thiourea under mild reaction conditions to afford enantioenriched synthetically and biologically important substituted
Organocatalytic Direct Asymmetric Vinylogous Michael Reaction of an α,β-Unsaturated γ-Butyrolactam with Enones
作者:Yong Zhang、Yong-Liang Shao、Hai-Sen Xu、Wei Wang
DOI:10.1021/jo102223v
日期:2011.3.4
An organocatalytic asymmetric directvinylogousMichaeladdition of α,β-unsaturated γ-butyrolactam to enones has been achieved with a simple bifunctional thiourea-tertiary amine catalyst, affording the γ-substituted butyrolactam products with high diastereo- and enantioselectivity (up to >40:1 dr and 94−99% ee).
An efficient synthetic route towards novel thienobenzothiazoles, thienobenzothiazepines, and thienobenzothiazines
作者:Wim Van Snick、Yelaman K. Aibuldinov、Wim Dehaen
DOI:10.1016/j.tet.2013.04.001
日期:2013.5
Efficient methods for the synthesis of novel nitrogen- and sulfur-containing heterocycles, annulated in the 4,5-position of benzothiophene, are described. Applying the Herz reaction, 3H-thienobenzodithiazole 2-oxide was prepared. This compound served as o-aminothiophenol precursor in the synthesis of a variety of thienobenzothiazoles, thienobenzothiazepines, thienobenzothiazines, and thienothiadiazole. (C) 2013 Elsevier Ltd. All rights reserved.